/* exif-entry.c
 *
 * Copyright (c) 2001 Lutz Mueller <lutz@users.sourceforge.net>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA  02110-1301  USA.
 */

#include <config.h>

#include <libexif/exif-entry.h>
#include <libexif/exif-ifd.h>
#include <libexif/exif-utils.h>
#include <libexif/i18n.h>

#include <ctype.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <time.h>
#include <math.h>
#include "port.h"

#ifndef M_PI
#define M_PI 3.14159265358979323846
#endif

struct _ExifEntryPrivate {
  unsigned int ref_count;

  ExifMem *mem;
};

/* This function is hidden in exif-data.c */
ExifLog *exif_data_get_log(ExifData *);

#ifndef NO_VERBOSE_TAG_STRINGS
static void
exif_entry_log(ExifEntry *e, ExifLogCode code, const char *format, ...)
{
  va_list args;
  ExifLog *l = NULL;

  if (e && e->parent && e->parent->parent) {
    l = exif_data_get_log(e->parent->parent);
  }
  va_start(args, format);
  exif_logv(l, code, "ExifEntry", format, args);
  va_end(args);
}
#else
#if defined(__STDC_VERSION__) &&  __STDC_VERSION__ >= 199901L
#define exif_entry_log(...) do { } while (0)
#elif defined(__GNUC__)
#define exif_entry_log(x...) do { } while (0)
#else
#define exif_entry_log (void)
#endif
#endif

static void *
exif_entry_alloc(ExifEntry *e, unsigned int i)
{
  void *d;
//  ExifLog *l = NULL;

  if (!e || !e->priv || !i) { return NULL; }

  d = exif_mem_alloc(e->priv->mem, i);
  if (d) { return d; }

  //if (e->parent && e->parent->parent)
  //  l = exif_data_get_log (e->parent->parent);
  //EXIF_LOG_NO_MEMORY (l, "ExifEntry", i);
  return NULL;
}

static void *
exif_entry_realloc(ExifEntry *e, void *d_orig, unsigned int i)
{
  void *d;
//  ExifLog *l = NULL;

  if (!e || !e->priv) { return NULL; }

  if (!i) { exif_mem_free(e->priv->mem, d_orig); return NULL; }

  d = exif_mem_realloc(e->priv->mem, d_orig, i);
  if (d) { return d; }

  //if (e->parent && e->parent->parent) {
  //  l = exif_data_get_log(e->parent->parent);
  //}
  //EXIF_LOG_NO_MEMORY(l, "ExifEntry", i);
  return NULL;
}

ExifEntry *
exif_entry_new(void)
{
  ExifMem *mem = exif_mem_new_default();
  ExifEntry *e = exif_entry_new_mem(mem);

  exif_mem_unref(mem);

  return e;
}

ExifEntry *
exif_entry_new_mem(ExifMem *mem)
{
  ExifEntry *e = NULL;

  e = exif_mem_alloc(mem, sizeof(ExifEntry));
  if (!e) { return NULL; }
  e->priv = exif_mem_alloc(mem, sizeof(ExifEntryPrivate));
  if (!e->priv) { exif_mem_free(mem, e); return NULL; }
  e->priv->ref_count = 1;

  e->priv->mem = mem;
  exif_mem_ref(mem);

  return e;
}

void
exif_entry_ref(ExifEntry *e)
{
  if (!e) { return; }

  e->priv->ref_count++;
}

void
exif_entry_unref(ExifEntry *e)
{
  if (!e) { return; }

  e->priv->ref_count--;
  if (!e->priv->ref_count) {
    exif_entry_free(e);
  }
}

void
exif_entry_free(ExifEntry *e)
{
  if (!e) { return; }

  if (e->priv) {
    ExifMem *mem = e->priv->mem;
    if (e->data) {
      exif_mem_free(mem, e->data);
    }
    exif_mem_free(mem, e->priv);
    exif_mem_free(mem, e);
    exif_mem_unref(mem);
  }
}

/*! Get a value and convert it to an ExifShort.
 * \bug Not all types are converted that could be converted and no indication
 *      is made when that occurs
 */
static ALWAYS_INLINE ExifShort
exif_get_short_convert(const unsigned char *buf, ExifFormat format,
                       ExifByteOrder order)
{
  switch (format) {
    case EXIF_FORMAT_LONG:
      return (ExifShort) exif_get_long(buf, order);
    case EXIF_FORMAT_SLONG:
      return (ExifShort) exif_get_slong(buf, order);
    case EXIF_FORMAT_SHORT:
      return (ExifShort) exif_get_short(buf, order);
    case EXIF_FORMAT_SSHORT:
      return (ExifShort) exif_get_sshort(buf, order);
    case EXIF_FORMAT_BYTE:
    case EXIF_FORMAT_SBYTE:
      return (ExifShort) buf[0];
    default:
      /* Unsupported type */
      return (ExifShort) 0;
  }
}

void
exif_entry_fix(ExifEntry *e)
{
  unsigned int i, newsize;
  unsigned char *newdata;
  ExifByteOrder o;
  ExifRational r;
  ExifSRational sr;

  if (!e || !e->priv) { return; }

  switch (e->tag) {

      /* These tags all need to be of format SHORT. */
    case EXIF_TAG_YCBCR_SUB_SAMPLING:
    case EXIF_TAG_SUBJECT_AREA:
    case EXIF_TAG_COLOR_SPACE:
    case EXIF_TAG_PLANAR_CONFIGURATION:
    case EXIF_TAG_SENSING_METHOD:
    case EXIF_TAG_ORIENTATION:
    case EXIF_TAG_YCBCR_POSITIONING:
    case EXIF_TAG_PHOTOMETRIC_INTERPRETATION:
    case EXIF_TAG_CUSTOM_RENDERED:
    case EXIF_TAG_EXPOSURE_MODE:
    case EXIF_TAG_WHITE_BALANCE:
    case EXIF_TAG_SCENE_CAPTURE_TYPE:
    case EXIF_TAG_GAIN_CONTROL:
    case EXIF_TAG_SATURATION:
    case EXIF_TAG_CONTRAST:
    case EXIF_TAG_SHARPNESS:
    case EXIF_TAG_ISO_SPEED_RATINGS:
      switch (e->format) {
        case EXIF_FORMAT_LONG:
        case EXIF_FORMAT_SLONG:
        case EXIF_FORMAT_BYTE:
        case EXIF_FORMAT_SBYTE:
        case EXIF_FORMAT_SSHORT:
          if (!e->parent || !e->parent->parent) { break; }
          exif_entry_log(e, EXIF_LOG_CODE_DEBUG,
                         _("Tag '%s' was of format '%s' (which is "
                           "against specification) and has been "
                           "changed to format '%s'."),
                         exif_tag_get_name_in_ifd(e->tag,
                                                  exif_entry_get_ifd(e)),
                         exif_format_get_name(e->format),
                         exif_format_get_name(EXIF_FORMAT_SHORT));

          o = exif_data_get_byte_order(e->parent->parent);
          newsize = e->components * exif_format_get_size(EXIF_FORMAT_SHORT);
          newdata = exif_entry_alloc(e, newsize);
          if (!newdata) {
            exif_entry_log(e, EXIF_LOG_CODE_NO_MEMORY,
                           "Could not allocate %lu byte(s).", (unsigned long)newsize);
            break;
          }

          for (i = 0; i < e->components; i++)
            exif_set_short(
              newdata + i *
              exif_format_get_size(
                EXIF_FORMAT_SHORT), o,
              exif_get_short_convert(
                e->data + i *
                exif_format_get_size(e->format),
                e->format, o));

          exif_mem_free(e->priv->mem, e->data);
          e->data = newdata;
          e->size = newsize;
          e->format = EXIF_FORMAT_SHORT;
          break;
        case EXIF_FORMAT_SHORT:
          /* No conversion necessary */
          break;
        default:
          exif_entry_log(e, EXIF_LOG_CODE_CORRUPT_DATA,
                         _("Tag '%s' is of format '%s' (which is "
                           "against specification) but cannot be changed "
                           "to format '%s'."),
                         exif_tag_get_name_in_ifd(e->tag,
                                                  exif_entry_get_ifd(e)),
                         exif_format_get_name(e->format),
                         exif_format_get_name(EXIF_FORMAT_SHORT));
          break;
      }
      break;

      /* All these tags need to be of format 'Rational'. */
    case EXIF_TAG_FNUMBER:
    case EXIF_TAG_APERTURE_VALUE:
    case EXIF_TAG_EXPOSURE_TIME:
    case EXIF_TAG_FOCAL_LENGTH:
      switch (e->format) {
        case EXIF_FORMAT_SRATIONAL:
          if (!e->parent || !e->parent->parent) { break; }
          o = exif_data_get_byte_order(e->parent->parent);
          for (i = 0; i < e->components; i++) {
            sr = exif_get_srational(e->data + i *
                                    exif_format_get_size(
                                      EXIF_FORMAT_SRATIONAL), o);
            r.numerator = (ExifLong) sr.numerator;
            r.denominator = (ExifLong) sr.denominator;
            exif_set_rational(e->data + i *
                              exif_format_get_size(
                                EXIF_FORMAT_RATIONAL), o, r);
          }
          e->format = EXIF_FORMAT_RATIONAL;
          exif_entry_log(e, EXIF_LOG_CODE_DEBUG,
                         _("Tag '%s' was of format '%s' (which is "
                           "against specification) and has been "
                           "changed to format '%s'."),
                         exif_tag_get_name_in_ifd(e->tag,
                                                  exif_entry_get_ifd(e)),
                         exif_format_get_name(EXIF_FORMAT_SRATIONAL),
                         exif_format_get_name(EXIF_FORMAT_RATIONAL));
          break;
        default:
          break;
      }
      break;

      /* All these tags need to be of format 'SRational'. */
    case EXIF_TAG_EXPOSURE_BIAS_VALUE:
    case EXIF_TAG_BRIGHTNESS_VALUE:
    case EXIF_TAG_SHUTTER_SPEED_VALUE:
      switch (e->format) {
        case EXIF_FORMAT_RATIONAL:
          if (!e->parent || !e->parent->parent) { break; }
          o = exif_data_get_byte_order(e->parent->parent);
          for (i = 0; i < e->components; i++) {
            r = exif_get_rational(e->data + i *
                                  exif_format_get_size(
                                    EXIF_FORMAT_RATIONAL), o);
            sr.numerator = (ExifLong) r.numerator;
            sr.denominator = (ExifLong) r.denominator;
            exif_set_srational(e->data + i *
                               exif_format_get_size(
                                 EXIF_FORMAT_SRATIONAL), o, sr);
          }
          e->format = EXIF_FORMAT_SRATIONAL;
          exif_entry_log(e, EXIF_LOG_CODE_DEBUG,
                         _("Tag '%s' was of format '%s' (which is "
                           "against specification) and has been "
                           "changed to format '%s'."),
                         exif_tag_get_name_in_ifd(e->tag,
                                                  exif_entry_get_ifd(e)),
                         exif_format_get_name(EXIF_FORMAT_RATIONAL),
                         exif_format_get_name(EXIF_FORMAT_SRATIONAL));
          break;
        default:
          break;
      }
      break;

    case EXIF_TAG_USER_COMMENT:

      /* Format needs to be UNDEFINED. */
      if (e->format != EXIF_FORMAT_UNDEFINED) {
        exif_entry_log(e, EXIF_LOG_CODE_DEBUG,
                       _("Tag 'UserComment' had invalid format '%s'. "
                         "Format has been set to 'undefined'."),
                       exif_format_get_name(e->format));
        e->format = EXIF_FORMAT_UNDEFINED;
      }

      /* Some packages like Canon ZoomBrowser EX 4.5 store
         only one zero byte followed by 7 bytes of rubbish */
      if ((e->size >= 8) && (e->data[0] == 0)) {
        memcpy(e->data, "\0\0\0\0\0\0\0\0", 8);
      }

      /* There need to be at least 8 bytes. */
      if (e->size < 8) {
        e->data = exif_entry_realloc(e, e->data, 8 + e->size);
        if (!e->data) {
          e->size = 0;
          e->components = 0;
          return;
        }

        /* Assume ASCII */
        memmove(e->data + 8, e->data, e->size);
        memcpy(e->data, "ASCII\0\0\0", 8);
        e->size += 8;
        e->components += 8;
        exif_entry_log(e, EXIF_LOG_CODE_DEBUG,
                       _("Tag 'UserComment' has been expanded to at "
                         "least 8 bytes in order to follow the "
                         "specification."));
        break;
      }

      /*
       * If the first 8 bytes are empty and real data starts
       * afterwards, let's assume ASCII and claim the 8 first
       * bytes for the format specifyer.
       */
      for (i = 0; (i < e->size) && !e->data[i]; i++);
      if (!i) for (; (i < e->size) && (e->data[i] == ' '); i++);
      if ((i >= 8) && (i < e->size)) {
        exif_entry_log(e, EXIF_LOG_CODE_DEBUG,
                       _("Tag 'UserComment' is not empty but does not "
                         "start with a format identifier. "
                         "This has been fixed."));
        memcpy(e->data, "ASCII\0\0\0", 8);
        break;
      }

      /*
       * First 8 bytes need to follow the specification. If they don't,
       * assume ASCII.
       */
      if (memcmp(e->data, "ASCII\0\0\0"     , 8) &&
          memcmp(e->data, "UNICODE\0"       , 8) &&
          memcmp(e->data, "JIS\0\0\0\0\0"   , 8) &&
          memcmp(e->data, "\0\0\0\0\0\0\0\0", 8)) {
        e->data = exif_entry_realloc(e, e->data, 8 + e->size);
        if (!e->data) {
          e->size = 0;
          e->components = 0;
          break;
        }

        /* Assume ASCII */
        memmove(e->data + 8, e->data, e->size);
        memcpy(e->data, "ASCII\0\0\0", 8);
        e->size += 8;
        e->components += 8;
        exif_entry_log(e, EXIF_LOG_CODE_DEBUG,
                       _("Tag 'UserComment' did not start with a "
                         "format identifier. This has been fixed."));
        break;
      }

      break;
    default:
      break;
  }
}

/*! Format the value of an ExifEntry for human display in a generic way.
 * The output is localized. The formatting is independent of the tag number
 * and is based entirely on the data type.
 * \pre The ExifEntry is already a member of an ExifData.
 * \param[in] e EXIF entry
 * \param[out] val buffer in which to store value
 * \param[in] maxlen one less than the length of the buffer val
 */
static void
exif_entry_format_value(ExifEntry *e, char *val, size_t maxlen)
{
  ExifByte v_byte;
  ExifShort v_short;
  ExifSShort v_sshort;
  ExifLong v_long;
  ExifRational v_rat;
  ExifSRational v_srat;
  ExifSLong v_slong;
  unsigned int i;
  size_t len;
  const ExifByteOrder o = exif_data_get_byte_order(e->parent->parent);

  if (!e->size || !maxlen) {
    return;
  }
  ++maxlen; /* include the terminating NUL */
  switch (e->format) {
    case EXIF_FORMAT_UNDEFINED:
      snprintf(val, maxlen, _("%i bytes undefined data"), e->size);
      break;
    case EXIF_FORMAT_BYTE:
    case EXIF_FORMAT_SBYTE:
      v_byte = e->data[0];
      snprintf(val, maxlen, "0x%02x", v_byte);
      len = strlen(val);
      for (i = 1; i < e->components; i++) {
        v_byte = e->data[i];
        snprintf(val + len, maxlen - len, ", 0x%02x", v_byte);
        len += strlen(val + len);
        if (len >= maxlen - 1) { break; }
      }
      break;
    case EXIF_FORMAT_SHORT:
      v_short = exif_get_short(e->data, o);
      snprintf(val, maxlen, "%u", v_short);
      len = strlen(val);
      for (i = 1; i < e->components; i++) {
        v_short = exif_get_short(e->data +
                                 exif_format_get_size(e->format) * i, o);
        snprintf(val + len, maxlen - len, ", %u", v_short);
        len += strlen(val + len);
        if (len >= maxlen - 1) { break; }
      }
      break;
    case EXIF_FORMAT_SSHORT:
      v_sshort = exif_get_sshort(e->data, o);
      snprintf(val, maxlen, "%i", v_sshort);
      len = strlen(val);
      for (i = 1; i < e->components; i++) {
        v_sshort = exif_get_short(e->data +
                                  exif_format_get_size(e->format) *
                                  i, o);
        snprintf(val + len, maxlen - len, ", %i", v_sshort);
        len += strlen(val + len);
        if (len >= maxlen - 1) { break; }
      }
      break;
    case EXIF_FORMAT_LONG:
      v_long = exif_get_long(e->data, o);
      snprintf(val, maxlen, "%lu", (unsigned long) v_long);
      len = strlen(val);
      for (i = 1; i < e->components; i++) {
        v_long = exif_get_long(e->data +
                               exif_format_get_size(e->format) *
                               i, o);
        snprintf(val + len, maxlen - len, ", %lu", (unsigned long) v_long);
        len += strlen(val + len);
        if (len >= maxlen - 1) { break; }
      }
      break;
    case EXIF_FORMAT_SLONG:
      v_slong = exif_get_slong(e->data, o);
      snprintf(val, maxlen, "%li", (long) v_slong);
      len = strlen(val);
      for (i = 1; i < e->components; i++) {
        v_slong = exif_get_slong(e->data +
                                 exif_format_get_size(e->format) * i, o);
        snprintf(val + len, maxlen - len, ", %li", (long) v_slong);
        len += strlen(val + len);
        if (len >= maxlen - 1) { break; }
      }
      break;
    case EXIF_FORMAT_ASCII:
      strncpy(val, (char *) e->data, MIN(maxlen - 1, e->size));
      val[MIN(maxlen - 1, e->size)] = 0;
      break;
    case EXIF_FORMAT_RATIONAL:
      len = 0;
      for (i = 0; i < e->components; i++) {
        if (i > 0) {
          snprintf(val + len, maxlen - len, ", ");
          len += strlen(val + len);
        }
        v_rat = exif_get_rational(
                  e->data + 8 * i, o);
        if (v_rat.denominator) {
          /*
           * Choose the number of significant digits to
           * display based on the size of the denominator.
           * It is scaled so that denominators within the
           * range 13..120 will show 2 decimal points.
           */
          int decimals = (int)(log10(v_rat.denominator) - 0.08 + 1.0);
          snprintf(val + len, maxlen - len, "%2.*f",
                   decimals,
                   (double) v_rat.numerator /
                   (double) v_rat.denominator);
        } else
          snprintf(val + len, maxlen - len, "%lu/%lu",
                   (unsigned long) v_rat.numerator,
                   (unsigned long) v_rat.denominator);
        len += strlen(val + len);
        if (len >= maxlen - 1) { break; }
      }
      break;
    case EXIF_FORMAT_SRATIONAL:
      len = 0;
      for (i = 0; i < e->components; i++) {
        if (i > 0) {
          snprintf(val + len, maxlen - len, ", ");
          len += strlen(val + len);
        }
        v_srat = exif_get_srational(
                   e->data + 8 * i, o);
        if (v_srat.denominator) {
          int decimals = (int)(log10(fabs(v_srat.denominator)) - 0.08 + 1.0);
          snprintf(val + len, maxlen - len, "%2.*f",
                   decimals,
                   (double) v_srat.numerator /
                   (double) v_srat.denominator);
        } else
          snprintf(val + len, maxlen - len, "%li/%li",
                   (long) v_srat.numerator,
                   (long) v_srat.denominator);
        len += strlen(val + len);
        if (len >= maxlen - 1) { break; }
      }
      break;
    case EXIF_FORMAT_DOUBLE:
    case EXIF_FORMAT_FLOAT:
    default:
      snprintf(val, maxlen, _("%i bytes unsupported data type"),
               e->size);
      break;
  }
}

void
exif_entry_dump(ExifEntry *e, unsigned int indent)
{
  char buf[1024];
  char value[1024];
  unsigned int i;

  for (i = 0; i < 2 * indent; i++) {
    buf[i] = ' ';
  }
  buf[i] = '\0';

  if (!e) {
    return;
  }

  printf("%sTag: 0x%x ('%s')\n", buf, e->tag,
         exif_tag_get_name_in_ifd(e->tag, exif_entry_get_ifd(e)));
  printf("%s  Format: %i ('%s')\n", buf, e->format,
         exif_format_get_name(e->format));
  printf("%s  Components: %i\n", buf, (int) e->components);
  printf("%s  Size: %i\n", buf, e->size);
  printf("%s  Value: %s\n", buf, exif_entry_get_value(e, value, sizeof(value)));
}

/*! Check if a string consists entirely of a single, repeated character.
 * Up to first n bytes are checked.
 *
 * \param[in] data pointer of string to check
 * \param[in] ch character to match
 * \param[in] n maximum number of characters to match
 *
 * \return 0 if the string matches or is of zero length, nonzero otherwise
 */
static int
match_repeated_char(const unsigned char *data, unsigned char ch, size_t n)
{
  int i;
  for (i = n; i; --i, ++data) {
    if (*data == 0) {
      i = 0;  /* all bytes before NUL matched */
      break;
    }
    if (*data != ch) {
      break;
    }
  }
  return i;
}

#define CF(entry,target,v,maxlen)         \
  {                 \
    if (entry->format != target) {          \
      exif_entry_log (entry, EXIF_LOG_CODE_CORRUPT_DATA,  \
                      _("The tag '%s' contains data of an invalid " \
                        "format ('%s', expected '%s')."),   \
                      exif_tag_get_name (entry->tag),     \
                      exif_format_get_name (entry->format),   \
                      exif_format_get_name (target));     \
      break;              \
    }               \
  }

#define CC(entry,target,v,maxlen)         \
  {                 \
    if (entry->components != target) {        \
      exif_entry_log (entry, EXIF_LOG_CODE_CORRUPT_DATA,  \
                      _("The tag '%s' contains an invalid number of " \
                        "components (%i, expected %i)."),   \
                      exif_tag_get_name (entry->tag),   \
                      (int) entry->components, (int) target);   \
      break;              \
    }               \
  }

static const struct {
  ExifTag tag;
  const char *strings[10];
} list[] = {
#ifndef NO_VERBOSE_TAG_DATA
  {
    EXIF_TAG_PLANAR_CONFIGURATION,
    { N_("Chunky format"), N_("Planar format"), NULL}
  },
  {
    EXIF_TAG_SENSING_METHOD,
    {
      "", N_("Not defined"), N_("One-chip color area sensor"),
      N_("Two-chip color area sensor"), N_("Three-chip color area sensor"),
      N_("Color sequential area sensor"), "", N_("Trilinear sensor"),
      N_("Color sequential linear sensor"), NULL
    }
  },
  {
    EXIF_TAG_ORIENTATION,
    {
      "", N_("Top-left"), N_("Top-right"), N_("Bottom-right"),
      N_("Bottom-left"), N_("Left-top"), N_("Right-top"),
      N_("Right-bottom"), N_("Left-bottom"), NULL
    }
  },
  {
    EXIF_TAG_YCBCR_POSITIONING,
    { "", N_("Centered"), N_("Co-sited"), NULL}
  },
  {
    EXIF_TAG_PHOTOMETRIC_INTERPRETATION,
    {
      N_("Reversed mono"), N_("Normal mono"), N_("RGB"), N_("Palette"), "",
      N_("CMYK"), N_("YCbCr"), "", N_("CieLAB"), NULL
    }
  },
  {
    EXIF_TAG_CUSTOM_RENDERED,
    { N_("Normal process"), N_("Custom process"), NULL}
  },
  {
    EXIF_TAG_EXPOSURE_MODE,
    { N_("Auto exposure"), N_("Manual exposure"), N_("Auto bracket"), NULL}
  },
  {
    EXIF_TAG_WHITE_BALANCE,
    { N_("Auto white balance"), N_("Manual white balance"), NULL}
  },
  {
    EXIF_TAG_SCENE_CAPTURE_TYPE,
    {
      N_("Standard"), N_("Landscape"), N_("Portrait"),
      N_("Night scene"), NULL
    }
  },
  {
    EXIF_TAG_GAIN_CONTROL,
    {
      N_("Normal"), N_("Low gain up"), N_("High gain up"),
      N_("Low gain down"), N_("High gain down"), NULL
    }
  },
  {
    EXIF_TAG_SATURATION,
    { N_("Normal"), N_("Low saturation"), N_("High saturation"), NULL}
  },
  { EXIF_TAG_CONTRAST , {N_("Normal"), N_("Soft"), N_("Hard"), NULL}},
  { EXIF_TAG_SHARPNESS, {N_("Normal"), N_("Soft"), N_("Hard"), NULL}},
#endif
  { 0, {NULL}}
};

static const struct {
  ExifTag tag;
  struct {
    int index;
    const char *values[4]; /*!< list of progressively shorter string
          descriptions; the longest one that fits will be
          selected */
  } elem[25];
} list2[] = {
#ifndef NO_VERBOSE_TAG_DATA
  {
    EXIF_TAG_METERING_MODE,
    { {  0, {N_("Unknown"), NULL}},
      {  1, {N_("Average"), N_("Avg"), NULL}},
      {  2, {N_("Center-weighted average"), N_("Center-weight"), NULL}},
      {  3, {N_("Spot"), NULL}},
      {  4, {N_("Multi spot"), NULL}},
      {  5, {N_("Pattern"), NULL}},
      {  6, {N_("Partial"), NULL}},
      {255, {N_("Other"), NULL}},
      {  0, {NULL}}
    }
  },
  {
    EXIF_TAG_COMPRESSION,
    { {1, {N_("Uncompressed"), NULL}},
      {5, {N_("LZW compression"), NULL}},
      {6, {N_("JPEG compression"), NULL}},
      {7, {N_("JPEG compression"), NULL}},
      {8, {N_("Deflate/ZIP compression"), NULL}},
      {32773, {N_("PackBits compression"), NULL}},
      {0, {NULL}}
    }
  },
  {
    EXIF_TAG_LIGHT_SOURCE,
    { {  0, {N_("Unknown"), NULL}},
      {  1, {N_("Daylight"), NULL}},
      {  2, {N_("Fluorescent"), NULL}},
      {  3, {N_("Tungsten incandescent light"), N_("Tungsten"), NULL}},
      {  4, {N_("Flash"), NULL}},
      {  9, {N_("Fine weather"), NULL}},
      { 10, {N_("Cloudy weather"), N_("Cloudy"), NULL}},
      { 11, {N_("Shade"), NULL}},
      { 12, {N_("Daylight fluorescent"), NULL}},
      { 13, {N_("Day white fluorescent"), NULL}},
      { 14, {N_("Cool white fluorescent"), NULL}},
      { 15, {N_("White fluorescent"), NULL}},
      { 17, {N_("Standard light A"), NULL}},
      { 18, {N_("Standard light B"), NULL}},
      { 19, {N_("Standard light C"), NULL}},
      { 20, {N_("D55"), NULL}},
      { 21, {N_("D65"), NULL}},
      { 22, {N_("D75"), NULL}},
      { 24, {N_("ISO studio tungsten"), NULL}},
      {255, {N_("Other"), NULL}},
      {  0, {NULL}}
    }
  },
  {
    EXIF_TAG_FOCAL_PLANE_RESOLUTION_UNIT,
    { {2, {N_("Inch"), N_("in"), NULL}},
      {3, {N_("Centimeter"), N_("cm"), NULL}},
      {0, {NULL}}
    }
  },
  {
    EXIF_TAG_RESOLUTION_UNIT,
    { {2, {N_("Inch"), N_("in"), NULL}},
      {3, {N_("Centimeter"), N_("cm"), NULL}},
      {0, {NULL}}
    }
  },
  {
    EXIF_TAG_EXPOSURE_PROGRAM,
    { {0, {N_("Not defined"), NULL}},
      {1, {N_("Manual"), NULL}},
      {2, {N_("Normal program"), N_("Normal"), NULL}},
      {3, {N_("Aperture priority"), N_("Aperture"), NULL}},
      {4, {N_("Shutter priority"), N_("Shutter"), NULL}},
      {
        5, {
          N_("Creative program (biased toward depth of field)"),
          N_("Creative"), NULL
        }
      },
      {
        6, {
          N_("Creative program (biased toward fast shutter speed)"),
          N_("Action"), NULL
        }
      },
      {
        7, {
          N_("Portrait mode (for closeup photos with the background out "
          "of focus)"), N_("Portrait"), NULL
        }
      },
      {
        8, {
          N_("Landscape mode (for landscape photos with the background "
          "in focus)"), N_("Landscape"), NULL
        }
      },
      {0, {NULL}}
    }
  },
  {
    EXIF_TAG_FLASH,
    { {0x0000, {N_("Flash did not fire"), N_("No flash"), NULL}},
      {0x0001, {N_("Flash fired"), N_("Flash"), N_("Yes"), NULL}},
      {
        0x0005, {
          N_("Strobe return light not detected"), N_("Without strobe"),
          NULL
        }
      },
      {0x0007, {N_("Strobe return light detected"), N_("With strobe"), NULL}},
      {0x0008, {N_("Flash did not fire"), NULL}}, /* Olympus E-330 */
      {0x0009, {N_("Flash fired, compulsory flash mode"), NULL}},
      {
        0x000d, {
          N_("Flash fired, compulsory flash mode, return light "
          "not detected"), NULL
        }
      },
      {
        0x000f, {
          N_("Flash fired, compulsory flash mode, return light "
          "detected"), NULL
        }
      },
      {0x0010, {N_("Flash did not fire, compulsory flash mode"), NULL}},
      {0x0018, {N_("Flash did not fire, auto mode"), NULL}},
      {0x0019, {N_("Flash fired, auto mode"), NULL}},
      {
        0x001d, {
          N_("Flash fired, auto mode, return light not detected"),
          NULL
        }
      },
      {0x001f, {N_("Flash fired, auto mode, return light detected"), NULL}},
      {0x0020, {N_("No flash function"), NULL}},
      {0x0041, {N_("Flash fired, red-eye reduction mode"), NULL}},
      {
        0x0045, {
          N_("Flash fired, red-eye reduction mode, return light "
          "not detected"), NULL
        }
      },
      {
        0x0047, {
          N_("Flash fired, red-eye reduction mode, return light "
          "detected"), NULL
        }
      },
      {
        0x0049, {
          N_("Flash fired, compulsory flash mode, red-eye reduction "
          "mode"), NULL
        }
      },
      {
        0x004d, {
          N_("Flash fired, compulsory flash mode, red-eye reduction "
          "mode, return light not detected"), NULL
        }
      },
      {
        0x004f, {
          N_("Flash fired, compulsory flash mode, red-eye reduction mode, "
          "return light detected"), NULL
        }
      },
      {0x0058, {N_("Flash did not fire, auto mode, red-eye reduction mode"), NULL}},
      {0x0059, {N_("Flash fired, auto mode, red-eye reduction mode"), NULL}},
      {
        0x005d, {
          N_("Flash fired, auto mode, return light not detected, "
          "red-eye reduction mode"), NULL
        }
      },
      {
        0x005f, {
          N_("Flash fired, auto mode, return light detected, "
          "red-eye reduction mode"), NULL
        }
      },
      {0x0000, {NULL}}
    }
  },
  {
    EXIF_TAG_SUBJECT_DISTANCE_RANGE,
    { {0, {N_("Unknown"), N_("?"), NULL}},
      {1, {N_("Macro"), NULL}},
      {2, {N_("Close view"), N_("Close"), NULL}},
      {3, {N_("Distant view"), N_("Distant"), NULL}},
      {0, {NULL}}
    }
  },
  {
    EXIF_TAG_COLOR_SPACE,
    { {1, {N_("sRGB"), NULL}},
      {2, {N_("Adobe RGB"), NULL}},
      {0xffff, {N_("Uncalibrated"), NULL}},
      {0x0000, {NULL}}
    }
  },
#endif
  {0, { { 0, {NULL}}} }
};

#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wswitch"

const char *
exif_entry_get_value(ExifEntry *e, char *val, unsigned int maxlen)
{
  unsigned int i, j, k;
  ExifShort v_short, v_short2, v_short3, v_short4;
  ExifByte v_byte;
  ExifRational v_rat;
  ExifSRational v_srat;
  char b[64];
  const char *c;
  ExifByteOrder o;
  double d;
  ExifEntry *entry;
  unsigned short *utf16;
  static const struct {
    char label[5];
    char major, minor;
  } versions[] = {
    {"0110", 1,  1},
    {"0120", 1,  2},
    {"0200", 2,  0},
    {"0210", 2,  1},
    {"0220", 2,  2},
    {"0221", 2, 21},
    {"0230", 2,  3},
    {""    , 0,  0}
  };

  /* FIXME: This belongs to somewhere else. */
  /* libexif should use the default system locale.
   * If an application specifically requires UTF-8, then we
   * must give the application a way to tell libexif that.
   *
   * bind_textdomain_codeset (GETTEXT_PACKAGE, "UTF-8");
   */
//  bindtextdomain(GETTEXT_PACKAGE, LOCALEDIR);

  if (!e || !e->parent || !e->parent->parent || !maxlen) {
    return val;
  }

  /* make sure the returned string is zero terminated */
  memset(val, 0, maxlen);
  maxlen--;
  memset(b, 0, sizeof(b));

  /* We need the byte order */
  o = exif_data_get_byte_order(e->parent->parent);

  /* Sanity check */
  if (e->size != e->components * exif_format_get_size(e->format)) {
    snprintf(val, maxlen, _("Invalid size of entry (%i, "
                            "expected %li x %i)."), e->size, e->components,
             exif_format_get_size(e->format));
    return val;
  }

  switch (e->tag) {
    case EXIF_TAG_USER_COMMENT:

      /*
       * The specification says UNDEFINED, but some
       * manufacturers don't care and use ASCII. If this is the
       * case here, only refuse to read it if there is no chance
       * of finding readable data.
       */
      if ((e->format != EXIF_FORMAT_ASCII) ||
          (e->size <= 8) ||
          (memcmp(e->data, "ASCII\0\0\0"  , 8) &&
           memcmp(e->data, "UNICODE\0"    , 8) &&
           memcmp(e->data, "JIS\0\0\0\0\0", 8) &&
           memcmp(e->data, "\0\0\0\0\0\0\0\0", 8))) {
        CF(e, EXIF_FORMAT_UNDEFINED, val, maxlen);
      }

      /*
       * Note that, according to the specification (V2.1, p 40),
       * the user comment field does not have to be
       * NULL terminated.
       */
      if ((e->size >= 8) && !memcmp(e->data, "ASCII\0\0\0", 8)) {
        strncpy(val, (char *) e->data + 8, MIN(e->size - 8, maxlen));
        break;
      }
      if ((e->size >= 8) && !memcmp(e->data, "UNICODE\0", 8)) {
        strncpy(val, _("Unsupported UNICODE string"), maxlen);
        /* FIXME: use iconv to convert into the locale encoding.
         * EXIF 2.2 implies (but does not say) that this encoding is
         * UCS-2.
         */
        break;
      }
      if ((e->size >= 8) && !memcmp(e->data, "JIS\0\0\0\0\0", 8)) {
        strncpy(val, _("Unsupported JIS string"), maxlen);
        /* FIXME: use iconv to convert into the locale encoding */
        break;
      }

      /* Check if there is really some information in the tag. */
      for (i = 0; (i < e->size) &&
           (!e->data[i] || (e->data[i] == ' ')); i++);
      if (i == e->size) { break; }

      /*
       * If we reach this point, the tag does not
       * comply with the standard but seems to contain data.
       * Print as much as possible.
       */
      exif_entry_log(e, EXIF_LOG_CODE_DEBUG,
                     _("Tag UserComment contains data but is "
                       "against specification."));
      for (j = 0; (i < e->size) && (j < maxlen); i++, j++) {
        exif_entry_log(e, EXIF_LOG_CODE_DEBUG,
                       _("Byte at position %i: 0x%02x"), i, e->data[i]);
        val[j] = isprint(e->data[i]) ? e->data[i] : '.';
      }
      break;

    case EXIF_TAG_EXIF_VERSION:
      CF(e, EXIF_FORMAT_UNDEFINED, val, maxlen);
      CC(e, 4, val, maxlen);
      strncpy(val, _("Unknown Exif Version"), maxlen);
      for (i = 0; *versions[i].label; i++) {
        if (!memcmp(e->data, versions[i].label, 4)) {
          snprintf(val, maxlen,
                   _("Exif Version %d.%d"),
                   versions[i].major,
                   versions[i].minor);
          break;
        }
      }
      break;
    case EXIF_TAG_FLASH_PIX_VERSION:
      CF(e, EXIF_FORMAT_UNDEFINED, val, maxlen);
      CC(e, 4, val, maxlen);
      if (!memcmp(e->data, "0100", 4)) {
        strncpy(val, _("FlashPix Version 1.0"), maxlen);
      } else if (!memcmp(e->data, "0101", 4)) {
        strncpy(val, _("FlashPix Version 1.01"), maxlen);
      } else {
        strncpy(val, _("Unknown FlashPix Version"), maxlen);
      }
      break;
    case EXIF_TAG_COPYRIGHT:
      CF(e, EXIF_FORMAT_ASCII, val, maxlen);

      /*
       * First part: Photographer.
       * Some cameras store a string like "   " here. Ignore it.
       * Remember that a corrupted tag might not be NUL-terminated
       */
      if (e->size && e->data && match_repeated_char(e->data, ' ', e->size)) {
        strncpy(val, (char *) e->data, MIN(maxlen, e->size));
      } else {
        strncpy(val, _("[None]"), maxlen);
      }
      strncat(val, " ", maxlen - strlen(val));
      strncat(val, _("(Photographer)"), maxlen - strlen(val));

      /* Second part: Editor. */
      strncat(val, " - ", maxlen - strlen(val));
      k = 0;
      if (e->size && e->data) {
        const unsigned char *tagdata = memchr(e->data, 0, e->size);
        if (tagdata++) {
          int editor_ofs = tagdata - e->data;
          int remaining = e->size - editor_ofs;
          if (match_repeated_char(tagdata, ' ', remaining)) {
            strncat(val, (const char *)tagdata, MIN(maxlen - strlen(val), remaining));
            ++k;
          }
        }
      }
      if (!k) {
        strncat(val, _("[None]"), maxlen - strlen(val));
      }
      strncat(val, " ", maxlen - strlen(val));
      strncat(val, _("(Editor)"), maxlen - strlen(val));

      break;
    case EXIF_TAG_FNUMBER:
      CF(e, EXIF_FORMAT_RATIONAL, val, maxlen);
      CC(e, 1, val, maxlen);
      v_rat = exif_get_rational(e->data, o);
      if (!v_rat.denominator) {
        exif_entry_format_value(e, val, maxlen);
        break;
      }
      d = (double) v_rat.numerator / (double) v_rat.denominator;
      snprintf(val, maxlen, "f/%.01f", d);
      break;
    case EXIF_TAG_APERTURE_VALUE:
    case EXIF_TAG_MAX_APERTURE_VALUE:
      CF(e, EXIF_FORMAT_RATIONAL, val, maxlen);
      CC(e, 1, val, maxlen);
      v_rat = exif_get_rational(e->data, o);
      if (!v_rat.denominator || (0x80000000 == v_rat.numerator)) {
        exif_entry_format_value(e, val, maxlen);
        break;
      }
      d = (double) v_rat.numerator / (double) v_rat.denominator;
      snprintf(val, maxlen, _("%.02f EV"), d);
      snprintf(b, sizeof(b), _(" (f/%.01f)"), pow(2, d / 2.));
      if (maxlen > strlen(val) + strlen(b)) {
        strncat(val, b, maxlen - strlen(val));
      }
      break;
    case EXIF_TAG_FOCAL_LENGTH:
      CF(e, EXIF_FORMAT_RATIONAL, val, maxlen);
      CC(e, 1, val, maxlen);
      v_rat = exif_get_rational(e->data, o);
      if (!v_rat.denominator) {
        exif_entry_format_value(e, val, maxlen);
        break;
      }

      /*
       * For calculation of the 35mm equivalent,
       * Minolta cameras need a multiplier that depends on the
       * camera model.
       */
      d = 0.;
      entry = exif_content_get_entry(
                e->parent->parent->ifd[EXIF_IFD_0], EXIF_TAG_MAKE);
      if (entry && entry->data &&
          !strncmp((char *)entry->data, "Minolta", 7)) {
        entry = exif_content_get_entry(
                  e->parent->parent->ifd[EXIF_IFD_0],
                  EXIF_TAG_MODEL);
        if (entry && entry->data) {
          if (!strncmp((char *)entry->data, "DiMAGE 7", 8)) {
            d = 3.9;
          } else if (!strncmp((char *)entry->data, "DiMAGE 5", 8)) {
            d = 4.9;
          }
        }
      }
      if (d)
        snprintf(b, sizeof(b), _(" (35 equivalent: %d mm)"),
                 (int)(d * (double) v_rat.numerator /
                       (double) v_rat.denominator));

      d = (double) v_rat.numerator / (double) v_rat.denominator;
      snprintf(val, maxlen, "%.1f mm", d);
      if (maxlen > strlen(val) + strlen(b)) {
        strncat(val, b, maxlen - strlen(val));
      }
      break;
    case EXIF_TAG_SUBJECT_DISTANCE:
      CF(e, EXIF_FORMAT_RATIONAL, val, maxlen);
      CC(e, 1, val, maxlen);
      v_rat = exif_get_rational(e->data, o);
      if (!v_rat.denominator) {
        exif_entry_format_value(e, val, maxlen);
        break;
      }
      d = (double) v_rat.numerator / (double) v_rat.denominator;
      snprintf(val, maxlen, "%.1f m", d);
      break;
    case EXIF_TAG_EXPOSURE_TIME:
      CF(e, EXIF_FORMAT_RATIONAL, val, maxlen);
      CC(e, 1, val, maxlen);
      v_rat = exif_get_rational(e->data, o);
      if (!v_rat.denominator) {
        exif_entry_format_value(e, val, maxlen);
        break;
      }
      d = (double) v_rat.numerator / (double) v_rat.denominator;
      if (d < 1) {
        snprintf(val, maxlen, _("1/%i"), (int)(0.5 + 1. / d));
      } else {
        snprintf(val, maxlen, "%i", (int) d);
      }
      if (maxlen > strlen(val) + strlen(_(" sec."))) {
        strncat(val, _(" sec."), maxlen - strlen(val));
      }
      break;
    case EXIF_TAG_SHUTTER_SPEED_VALUE:
      CF(e, EXIF_FORMAT_SRATIONAL, val, maxlen);
      CC(e, 1, val, maxlen);
      v_srat = exif_get_srational(e->data, o);
      if (!v_srat.denominator) {
        exif_entry_format_value(e, val, maxlen);
        break;
      }
      d = (double) v_srat.numerator / (double) v_srat.denominator;
      snprintf(val, maxlen, _("%.02f EV"), d);
      d = 1. / pow(2, d);
      if (d < 1) {
        snprintf(b, sizeof(b), _(" (1/%d sec.)"), (int)(1. / d));
      } else {
        snprintf(b, sizeof(b), _(" (%d sec.)"), (int) d);
      }
      strncat(val, b, maxlen - strlen(val));
      break;
    case EXIF_TAG_BRIGHTNESS_VALUE:
      CF(e, EXIF_FORMAT_SRATIONAL, val, maxlen);
      CC(e, 1, val, maxlen);
      v_srat = exif_get_srational(e->data, o);
      if (!v_srat.denominator) {
        exif_entry_format_value(e, val, maxlen);
        break;
      }
      d = (double) v_srat.numerator / (double) v_srat.denominator;
      snprintf(val, maxlen, _("%.02f EV"), d);
      snprintf(b, sizeof(b), _(" (%.02f cd/m^2)"),
               1. / (M_PI * 0.3048 * 0.3048) * pow(2, d));
      if (maxlen > strlen(val) + strlen(b)) {
        strncat(val, b, maxlen - strlen(val));
      }
      break;
    case EXIF_TAG_FILE_SOURCE:
      CF(e, EXIF_FORMAT_UNDEFINED, val, maxlen);
      CC(e, 1, val, maxlen);
      v_byte = e->data[0];
      if (v_byte == 3) {
        strncpy(val, _("DSC"), maxlen);
      } else
        snprintf(val, maxlen, _("Internal error (unknown "
                                "value %i)"), v_byte);
      break;
    case EXIF_TAG_COMPONENTS_CONFIGURATION:
      CF(e, EXIF_FORMAT_UNDEFINED, val, maxlen);
      CC(e, 4, val, maxlen);
      for (i = 0; i < 4; i++) {
        switch (e->data[i]) {
          case 0: c = _("-"); break;
          case 1: c = _("Y"); break;
          case 2: c = _("Cb"); break;
          case 3: c = _("Cr"); break;
          case 4: c = _("R"); break;
          case 5: c = _("G"); break;
          case 6: c = _("B"); break;
          default: c = _("Reserved"); break;
        }
        strncat(val, c, maxlen - strlen(val));
        if (i < 3) {
          strncat(val, " ", maxlen - strlen(val));
        }
      }
      break;
    case EXIF_TAG_EXPOSURE_BIAS_VALUE:
      CF(e, EXIF_FORMAT_SRATIONAL, val, maxlen);
      CC(e, 1, val, maxlen);
      v_srat = exif_get_srational(e->data, o);
      if (!v_srat.denominator) {
        exif_entry_format_value(e, val, maxlen);
        break;
      }
      d = (double) v_srat.numerator / (double) v_srat.denominator;
      snprintf(val, maxlen, _("%.02f EV"), d);
      break;
    case EXIF_TAG_SCENE_TYPE:
      CF(e, EXIF_FORMAT_UNDEFINED, val, maxlen);
      CC(e, 1, val, maxlen);
      v_byte = e->data[0];
      if (v_byte == 1) {
        strncpy(val, _("Directly photographed"), maxlen);
      } else
        snprintf(val, maxlen, _("Internal error (unknown "
                                "value %i)"), v_byte);
      break;
    case EXIF_TAG_YCBCR_SUB_SAMPLING:
      CF(e, EXIF_FORMAT_SHORT, val, maxlen);
      CC(e, 2, val, maxlen);
      v_short  = exif_get_short(e->data, o);
      v_short2 = exif_get_short(
                   e->data + exif_format_get_size(e->format),
                   o);
      if ((v_short == 2) && (v_short2 == 1)) {
        strncpy(val, _("YCbCr4:2:2"), maxlen);
      } else if ((v_short == 2) && (v_short2 == 2)) {
        strncpy(val, _("YCbCr4:2:0"), maxlen);
      } else {
        snprintf(val, maxlen, "%u, %u", v_short, v_short2);
      }
      break;
    case EXIF_TAG_SUBJECT_AREA:
      CF(e, EXIF_FORMAT_SHORT, val, maxlen);
      switch (e->components) {
        case 2:
          v_short  = exif_get_short(e->data, o);
          v_short2 = exif_get_short(e->data + 2, o);
          snprintf(val, maxlen, "(x,y) = (%i,%i)",
                   v_short, v_short2);
          break;
        case 3:
          v_short  = exif_get_short(e->data, o);
          v_short2 = exif_get_short(e->data + 2, o);
          v_short3 = exif_get_short(e->data + 4, o);
          snprintf(val, maxlen, _("Within distance %i of "
                                  "(x,y) = (%i,%i)"), v_short3, v_short,
                   v_short2);
          break;
        case 4:
          v_short  = exif_get_short(e->data, o);
          v_short2 = exif_get_short(e->data + 2, o);
          v_short3 = exif_get_short(e->data + 4, o);
          v_short4 = exif_get_short(e->data + 6, o);
          snprintf(val, maxlen, _("Within rectangle "
                                  "(width %i, height %i) around "
                                  "(x,y) = (%i,%i)"), v_short3, v_short4,
                   v_short, v_short2);
          break;
        default:
          snprintf(val, maxlen, _("Unexpected number "
                                  "of components (%li, expected 2, 3, or 4)."),
                   e->components);
      }
      break;
    case EXIF_TAG_GPS_VERSION_ID:
      /* This is only valid in the GPS IFD */
      CF(e, EXIF_FORMAT_BYTE, val, maxlen);
      CC(e, 4, val, maxlen);
      v_byte = e->data[0];
      snprintf(val, maxlen, "%u", v_byte);
      maxlen -= strlen(val);
      for (i = 1; i < e->components; i++) {
        v_byte = e->data[i];
        snprintf(b, sizeof(b), ".%u", v_byte);
        strncat(val, b, maxlen);
        maxlen -= strlen(b);
        if ((signed)maxlen <= 0) { break; }
      }
      break;
    case EXIF_TAG_INTEROPERABILITY_VERSION:
      /* a.k.a. case EXIF_TAG_GPS_LATITUDE: */
      /* This tag occurs in EXIF_IFD_INTEROPERABILITY */
      if (e->format == EXIF_FORMAT_UNDEFINED) {
        strncpy(val, (char *) e->data, MIN(maxlen, e->size));
        break;
      }
      /* EXIF_TAG_GPS_LATITUDE is the same numerically as
       * EXIF_TAG_INTEROPERABILITY_VERSION but in EXIF_IFD_GPS
       */
      exif_entry_format_value(e, val, maxlen);
      break;
    case EXIF_TAG_GPS_ALTITUDE_REF:
      /* This is only valid in the GPS IFD */
      CF(e, EXIF_FORMAT_BYTE, val, maxlen);
      CC(e, 1, val, maxlen);
      v_byte = e->data[0];
      if (v_byte == 0) {
        strncpy(val, _("Sea level"), maxlen);
      } else if (v_byte == 1) {
        strncpy(val, _("Sea level reference"), maxlen);
      } else
        snprintf(val, maxlen, _("Internal error (unknown "
                                "value %i)"), v_byte);
      break;
    case EXIF_TAG_GPS_TIME_STAMP:
      /* This is only valid in the GPS IFD */
      CF(e, EXIF_FORMAT_RATIONAL, val, maxlen);
      CC(e, 3, val, maxlen);

      v_rat  = exif_get_rational(e->data, o);
      if (!v_rat.denominator) {
        exif_entry_format_value(e, val, maxlen);
        break;
      }
      i = v_rat.numerator / v_rat.denominator;

      v_rat = exif_get_rational(e->data +
                                exif_format_get_size(e->format),
                                o);
      if (!v_rat.denominator) {
        exif_entry_format_value(e, val, maxlen);
        break;
      }
      j = v_rat.numerator / v_rat.denominator;

      v_rat = exif_get_rational(e->data +
                                2 * exif_format_get_size(e->format),
                                o);
      if (!v_rat.denominator) {
        exif_entry_format_value(e, val, maxlen);
        break;
      }
      d = (double) v_rat.numerator / (double) v_rat.denominator;
      snprintf(val, maxlen, "%02u:%02u:%05.2f", i, j, d);
      break;

    case EXIF_TAG_METERING_MODE:
    case EXIF_TAG_COMPRESSION:
    case EXIF_TAG_LIGHT_SOURCE:
    case EXIF_TAG_FOCAL_PLANE_RESOLUTION_UNIT:
    case EXIF_TAG_RESOLUTION_UNIT:
    case EXIF_TAG_EXPOSURE_PROGRAM:
    case EXIF_TAG_FLASH:
    case EXIF_TAG_SUBJECT_DISTANCE_RANGE:
    case EXIF_TAG_COLOR_SPACE:
      CF(e, EXIF_FORMAT_SHORT, val, maxlen);
      CC(e, 1, val, maxlen);
      v_short = exif_get_short(e->data, o);

      /* Search the tag */
      for (i = 0; list2[i].tag && (list2[i].tag != e->tag); i++);
      if (!list2[i].tag) {
        snprintf(val, maxlen, _("Internal error (unknown "
                                "value %i)"), v_short);
        break;
      }

      /* Find the value */
      for (j = 0; list2[i].elem[j].values[0] &&
           (list2[i].elem[j].index < v_short); j++);
      if (list2[i].elem[j].index != v_short) {
        snprintf(val, maxlen, _("Internal error (unknown "
                                "value %i)"), v_short);
        break;
      }

      /* Find a short enough value */
      memset(val, 0, maxlen);
      for (k = 0; list2[i].elem[j].values[k]; k++) {
        size_t l = strlen(_(list2[i].elem[j].values[k]));
        if ((maxlen > l) && (strlen(val) < l)) {
          strncpy(val, _(list2[i].elem[j].values[k]), maxlen);
        }
      }
      if (!val[0]) { snprintf(val, maxlen, "%i", v_short); }

      break;

    case EXIF_TAG_PLANAR_CONFIGURATION:
    case EXIF_TAG_SENSING_METHOD:
    case EXIF_TAG_ORIENTATION:
    case EXIF_TAG_YCBCR_POSITIONING:
    case EXIF_TAG_PHOTOMETRIC_INTERPRETATION:
    case EXIF_TAG_CUSTOM_RENDERED:
    case EXIF_TAG_EXPOSURE_MODE:
    case EXIF_TAG_WHITE_BALANCE:
    case EXIF_TAG_SCENE_CAPTURE_TYPE:
    case EXIF_TAG_GAIN_CONTROL:
    case EXIF_TAG_SATURATION:
    case EXIF_TAG_CONTRAST:
    case EXIF_TAG_SHARPNESS:
      CF(e, EXIF_FORMAT_SHORT, val, maxlen);
      CC(e, 1, val, maxlen);
      v_short = exif_get_short(e->data, o);

      /* Search the tag */
      for (i = 0; list[i].tag && (list[i].tag != e->tag); i++);
      if (!list[i].tag) {
        snprintf(val, maxlen, _("Internal error (unknown "
                                "value %i)"), v_short);
        break;
      }

      /* Find the value */
      for (j = 0; list[i].strings[j] && (j < v_short); j++);
      if (!list[i].strings[j]) {
        snprintf(val, maxlen, "%i", v_short);
      } else if (!*list[i].strings[j]) {
        snprintf(val, maxlen, _("Unknown value %i"), v_short);
      } else {
        strncpy(val, _(list[i].strings[j]), maxlen);
      }
      break;

    case EXIF_TAG_XP_TITLE:
    case EXIF_TAG_XP_COMMENT:
    case EXIF_TAG_XP_AUTHOR:
    case EXIF_TAG_XP_KEYWORDS:
    case EXIF_TAG_XP_SUBJECT: {
      /* Sanity check the size to prevent overflow */
      if (e->size + sizeof(unsigned short) < e->size) { break; }

      /* The tag may not be U+0000-terminated , so make a local
         U+0000-terminated copy before converting it */
      utf16 = exif_mem_alloc(e->priv->mem, e->size + sizeof(unsigned short));
      if (!utf16) { break; }
      memcpy(utf16, e->data, e->size);
      utf16[e->size / sizeof(unsigned short)] = 0;

      /* Warning! The texts are converted from UTF16 to UTF8 */
      /* FIXME: use iconv to convert into the locale encoding */
      exif_convert_utf16_to_utf8(val, utf16, maxlen);
      exif_mem_free(e->priv->mem, utf16);
      break;
    }

    default:
      /* Use a generic value formatting */
      exif_entry_format_value(e, val, maxlen);
  }

  return val;
}
#pragma GCC diagnostic pop

/*!
 * \bug Log and report failed exif_mem_malloc() calls.
 */
void
exif_entry_initialize(ExifEntry *e, ExifTag tag)
{
  ExifRational r;
  ExifByteOrder o;

  /* We need the byte order */
  if (!e || !e->parent || e->data || !e->parent->parent) {
    return;
  }
  o = exif_data_get_byte_order(e->parent->parent);

  e->tag = tag;
  switch (tag) {

      /* LONG, 1 component, no default */
    case EXIF_TAG_PIXEL_X_DIMENSION:
    case EXIF_TAG_PIXEL_Y_DIMENSION:
    case EXIF_TAG_EXIF_IFD_POINTER:
    case EXIF_TAG_GPS_INFO_IFD_POINTER:
    case EXIF_TAG_INTEROPERABILITY_IFD_POINTER:
    case EXIF_TAG_JPEG_INTERCHANGE_FORMAT_LENGTH:
    case EXIF_TAG_JPEG_INTERCHANGE_FORMAT:
      e->components = 1;
      e->format = EXIF_FORMAT_LONG;
      e->size = exif_format_get_size(e->format) * e->components;
      e->data = exif_entry_alloc(e, e->size);
      if (!e->data) { break; }
      break;

      /* SHORT, 1 component, no default */
    case EXIF_TAG_SUBJECT_LOCATION:
    case EXIF_TAG_SENSING_METHOD:
    case EXIF_TAG_PHOTOMETRIC_INTERPRETATION:
    case EXIF_TAG_COMPRESSION:
    case EXIF_TAG_EXPOSURE_MODE:
    case EXIF_TAG_WHITE_BALANCE:
    case EXIF_TAG_FOCAL_LENGTH_IN_35MM_FILM:
    case EXIF_TAG_GAIN_CONTROL:
    case EXIF_TAG_SUBJECT_DISTANCE_RANGE:
    case EXIF_TAG_FLASH:
    case EXIF_TAG_ISO_SPEED_RATINGS:

      /* SHORT, 1 component, default 0 */
    case EXIF_TAG_IMAGE_WIDTH:
    case EXIF_TAG_IMAGE_LENGTH:
    case EXIF_TAG_EXPOSURE_PROGRAM:
    case EXIF_TAG_LIGHT_SOURCE:
    case EXIF_TAG_METERING_MODE:
    case EXIF_TAG_CUSTOM_RENDERED:
    case EXIF_TAG_SCENE_CAPTURE_TYPE:
    case EXIF_TAG_CONTRAST:
    case EXIF_TAG_SATURATION:
    case EXIF_TAG_SHARPNESS:
      e->components = 1;
      e->format = EXIF_FORMAT_SHORT;
      e->size = exif_format_get_size(e->format) * e->components;
      e->data = exif_entry_alloc(e, e->size);
      if (!e->data) { break; }
      exif_set_short(e->data, o, 0);
      break;

      /* SHORT, 1 component, default 1 */
    case EXIF_TAG_ORIENTATION:
    case EXIF_TAG_PLANAR_CONFIGURATION:
    case EXIF_TAG_YCBCR_POSITIONING:
      e->components = 1;
      e->format = EXIF_FORMAT_SHORT;
      e->size = exif_format_get_size(e->format) * e->components;
      e->data = exif_entry_alloc(e, e->size);
      if (!e->data) { break; }
      exif_set_short(e->data, o, 1);
      break;

      /* SHORT, 1 component, default 2 */
    case EXIF_TAG_RESOLUTION_UNIT:
    case EXIF_TAG_FOCAL_PLANE_RESOLUTION_UNIT:
      e->components = 1;
      e->format = EXIF_FORMAT_SHORT;
      e->size = exif_format_get_size(e->format) * e->components;
      e->data = exif_entry_alloc(e, e->size);
      if (!e->data) { break; }
      exif_set_short(e->data, o, 2);
      break;

      /* SHORT, 1 component, default 3 */
    case EXIF_TAG_SAMPLES_PER_PIXEL:
      e->components = 1;
      e->format = EXIF_FORMAT_SHORT;
      e->size = exif_format_get_size(e->format) * e->components;
      e->data = exif_entry_alloc(e, e->size);
      if (!e->data) { break; }
      exif_set_short(e->data, o, 3);
      break;

      /* SHORT, 1 component, default 0xffff */
    case EXIF_TAG_COLOR_SPACE:
      e->components = 1;
      e->format = EXIF_FORMAT_SHORT;
      e->size = exif_format_get_size(e->format) * e->components;
      e->data = exif_entry_alloc(e, e->size);
      if (!e->data) { break; }
      exif_set_short(e->data, o, 0xffff);
      break;

      /* SHORT, 3 components, default 8 8 8 */
    case EXIF_TAG_BITS_PER_SAMPLE:
      e->components = 3;
      e->format = EXIF_FORMAT_SHORT;
      e->size = exif_format_get_size(e->format) * e->components;
      e->data = exif_entry_alloc(e, e->size);
      if (!e->data) { break; }
      exif_set_short(e->data, o, 8);
      exif_set_short(
        e->data + exif_format_get_size(e->format),
        o, 8);
      exif_set_short(
        e->data + 2 * exif_format_get_size(e->format),
        o, 8);
      break;

      /* SHORT, 2 components, default 2 1 */
    case EXIF_TAG_YCBCR_SUB_SAMPLING:
      e->components = 2;
      e->format = EXIF_FORMAT_SHORT;
      e->size = exif_format_get_size(e->format) * e->components;
      e->data = exif_entry_alloc(e, e->size);
      if (!e->data) { break; }
      exif_set_short(e->data, o, 2);
      exif_set_short(
        e->data + exif_format_get_size(e->format),
        o, 1);
      break;

      /* SRATIONAL, 1 component, no default */
    case EXIF_TAG_EXPOSURE_BIAS_VALUE:
    case EXIF_TAG_BRIGHTNESS_VALUE:
    case EXIF_TAG_SHUTTER_SPEED_VALUE:
      e->components = 1;
      e->format = EXIF_FORMAT_SRATIONAL;
      e->size = exif_format_get_size(e->format) * e->components;
      e->data = exif_entry_alloc(e, e->size);
      if (!e->data) { break; }
      break;

      /* RATIONAL, 1 component, no default */
    case EXIF_TAG_EXPOSURE_TIME:
    case EXIF_TAG_FOCAL_PLANE_X_RESOLUTION:
    case EXIF_TAG_FOCAL_PLANE_Y_RESOLUTION:
    case EXIF_TAG_EXPOSURE_INDEX:
    case EXIF_TAG_FLASH_ENERGY:
    case EXIF_TAG_FNUMBER:
    case EXIF_TAG_FOCAL_LENGTH:
    case EXIF_TAG_SUBJECT_DISTANCE:
    case EXIF_TAG_MAX_APERTURE_VALUE:
    case EXIF_TAG_APERTURE_VALUE:
    case EXIF_TAG_COMPRESSED_BITS_PER_PIXEL:
    case EXIF_TAG_PRIMARY_CHROMATICITIES:
    case EXIF_TAG_DIGITAL_ZOOM_RATIO:
      e->components = 1;
      e->format = EXIF_FORMAT_RATIONAL;
      e->size = exif_format_get_size(e->format) * e->components;
      e->data = exif_entry_alloc(e, e->size);
      if (!e->data) { break; }
      break;

      /* RATIONAL, 1 component, default 72/1 */
    case EXIF_TAG_X_RESOLUTION:
    case EXIF_TAG_Y_RESOLUTION:
      e->components = 1;
      e->format = EXIF_FORMAT_RATIONAL;
      e->size = exif_format_get_size(e->format) * e->components;
      e->data = exif_entry_alloc(e, e->size);
      if (!e->data) { break; }
      r.numerator = 72;
      r.denominator = 1;
      exif_set_rational(e->data, o, r);
      break;

      /* RATIONAL, 2 components, no default */
    case EXIF_TAG_WHITE_POINT:
      e->components = 2;
      e->format = EXIF_FORMAT_RATIONAL;
      e->size = exif_format_get_size(e->format) * e->components;
      e->data = exif_entry_alloc(e, e->size);
      if (!e->data) { break; }
      break;

      /* RATIONAL, 6 components */
    case EXIF_TAG_REFERENCE_BLACK_WHITE:
      e->components = 6;
      e->format = EXIF_FORMAT_RATIONAL;
      e->size = exif_format_get_size(e->format) * e->components;
      e->data = exif_entry_alloc(e, e->size);
      if (!e->data) { break; }
      r.denominator = 1;
      r.numerator = 0;
      exif_set_rational(e->data, o, r);
      r.numerator = 255;
      exif_set_rational(
        e->data + exif_format_get_size(e->format), o, r);
      r.numerator = 0;
      exif_set_rational(
        e->data + 2 * exif_format_get_size(e->format), o, r);
      r.numerator = 255;
      exif_set_rational(
        e->data + 3 * exif_format_get_size(e->format), o, r);
      r.numerator = 0;
      exif_set_rational(
        e->data + 4 * exif_format_get_size(e->format), o, r);
      r.numerator = 255;
      exif_set_rational(
        e->data + 5 * exif_format_get_size(e->format), o, r);
      break;

      /* ASCII, 20 components */
    case EXIF_TAG_DATE_TIME:
    case EXIF_TAG_DATE_TIME_ORIGINAL:
    case EXIF_TAG_DATE_TIME_DIGITIZED: {
      time_t t;
#ifdef HAVE_LOCALTIME_R
      struct tm tms;
#endif
      struct tm *tm;

      t = time(NULL);
#ifdef HAVE_LOCALTIME_R
      tm = localtime_r(&t, &tms);
#else
      tm = localtime(&t);
#endif
      e->components = 20;
      e->format = EXIF_FORMAT_ASCII;
      e->size = exif_format_get_size(e->format) * e->components;
      e->data = exif_entry_alloc(e, e->size);
      if (!e->data) { break; }
      snprintf((char *) e->data, e->size,
               "%04i:%02i:%02i %02i:%02i:%02i",
               tm->tm_year + 1900, tm->tm_mon + 1, tm->tm_mday,
               tm->tm_hour, tm->tm_min, tm->tm_sec);
      break;
    }

    /* ASCII, no default */
    case EXIF_TAG_SUB_SEC_TIME:
    case EXIF_TAG_SUB_SEC_TIME_ORIGINAL:
    case EXIF_TAG_SUB_SEC_TIME_DIGITIZED:
      e->components = 0;
      e->format = EXIF_FORMAT_ASCII;
      e->size = 0;
      e->data = NULL;
      break;

      /* ASCII, default "[None]" */
    case EXIF_TAG_IMAGE_DESCRIPTION:
    case EXIF_TAG_MAKE:
    case EXIF_TAG_MODEL:
    case EXIF_TAG_SOFTWARE:
    case EXIF_TAG_ARTIST:
      e->components = strlen(_("[None]")) + 1;
      e->format = EXIF_FORMAT_ASCII;
      e->size = exif_format_get_size(e->format) * e->components;
      e->data = exif_entry_alloc(e, e->size);
      if (!e->data) { break; }
      strncpy((char *)e->data, _("[None]"), e->size);
      break;
      /* ASCII, default "[None]\0[None]\0" */
    case EXIF_TAG_COPYRIGHT:
      e->components = (strlen(_("[None]")) + 1) * 2;
      e->format = EXIF_FORMAT_ASCII;
      e->size = exif_format_get_size(e->format) * e->components;
      e->data = exif_entry_alloc(e, e->size);
      if (!e->data) { break; }
      strcpy(((char *)e->data) + 0, _("[None]"));
      strcpy(((char *)e->data) + strlen(_("[None]")) + 1, _("[None]"));
      break;

      /* UNDEFINED, 1 component, default 1 */
    case EXIF_TAG_SCENE_TYPE:
      e->components = 1;
      e->format = EXIF_FORMAT_UNDEFINED;
      e->size = exif_format_get_size(e->format) * e->components;
      e->data = exif_entry_alloc(e, e->size);
      if (!e->data) { break; }
      e->data[0] = 0x01;
      break;

      /* UNDEFINED, 1 component, default 3 */
    case EXIF_TAG_FILE_SOURCE:
      e->components = 1;
      e->format = EXIF_FORMAT_UNDEFINED;
      e->size = exif_format_get_size(e->format) * e->components;
      e->data = exif_entry_alloc(e, e->size);
      if (!e->data) { break; }
      e->data[0] = 0x03;
      break;

      /* UNDEFINED, 4 components, default 48 49 48 48 */
    case EXIF_TAG_FLASH_PIX_VERSION:
      e->components = 4;
      e->format = EXIF_FORMAT_UNDEFINED;
      e->size = exif_format_get_size(e->format) * e->components;
      e->data = exif_entry_alloc(e, e->size);
      if (!e->data) { break; }
      memcpy(e->data, "0100", 4);
      break;

      /* UNDEFINED, 4 components, default 48 50 49 48 */
    case EXIF_TAG_EXIF_VERSION:
      e->components = 4;
      e->format = EXIF_FORMAT_UNDEFINED;
      e->size = exif_format_get_size(e->format) * e->components;
      e->data = exif_entry_alloc(e, e->size);
      if (!e->data) { break; }
      memcpy(e->data, "0210", 4);
      break;

      /* UNDEFINED, 4 components, default 1 2 3 0 */
    case EXIF_TAG_COMPONENTS_CONFIGURATION:
      e->components = 4;
      e->format = EXIF_FORMAT_UNDEFINED;
      e->size = exif_format_get_size(e->format) * e->components;
      e->data = exif_entry_alloc(e, e->size);
      if (!e->data) { break; }
      e->data[0] = 1;
      e->data[1] = 2;
      e->data[2] = 3;
      e->data[3] = 0;
      break;

      /* UNDEFINED, no components, no default */
      /* Use this if the tag is otherwise unsupported */
    case EXIF_TAG_MAKER_NOTE:
    case EXIF_TAG_USER_COMMENT:
    default:
      e->components = 0;
      e->format = EXIF_FORMAT_UNDEFINED;
      e->size = 0;
      e->data = NULL;
      break;
  }
}
